1. Filed of the Invention
The present invention relates to a jack which is to be used for inputting and outputting a video/audio signal in an electronic apparatus such as a portable telephone, a digital camera, or portable audio equipment, and more particularly to a jack having a switch mechanism of the single-butt contact type in which an ON/OFF operation is performed by insertion/extraction of a plug.
2. Description of the Prior Art
As a conventional art of a jack of this type, Japanese Utility Model Registration No. 2,551,276 and Japanese Utility Model Application Laying-Open No. 5-17964 disclose a jack having a switch mechanism of the single-butt contact type having a structure which is configured by: two contact pieces that are opposed to each other outside a plug insertion hole so that, when a plug is inserted, the contact pieces are not contacted with the plug; and an insulator that is projected in the plug insertion hole so that, when the plug is inserted, the insulator is pressed by the plug to be displaced, and in which, when the plug is inserted, a displacement load is applied by the insulator to a tip end portion of an inner one of the contact pieces to flex the inner contact piece while setting a basal end portion of the contact piece as a fulcrum, whereby the tip end portion is contacted with a tip end portion of the outer contact piece, and thereafter the tip end portion of the outer contact piece is pressed by the tip end portion of the inner contact piece to flex the outer contact piece while setting a basal end portion of the contact piece as a fulcrum, to apply a contact pressure on a contact. In the conventional art, therefore, a portion where the insulator serving as a jack body is incorporated into the switch mechanism is largely outward projected, and an incorporation space for the switch mechanism having a contact displacement space is ensured also in the outside of the outer contact piece. As both of the two contact pieces, plate springs which are produced by punching and bending a thin metal plate having spring characteristics, and which function as movable contact pieces are used.